1 Field of the Invention
The present invention relates to a wireless communication apparatus and a wireless communication method, in particular, to a wireless communication apparatus and a wireless communication method for performing cognitive radio communication using frequency hopping.
2 Related Art
In conventional wireless communication using frequency hopping, there is a following communication method as an example. In the method, radio wave environments (received levels) of available frequency channels in a plurality of frequency channels are measured, the available frequency channels are ranked in ascending order of received level, and communication is performed by frequency hopping in this order (see JP-A 1997-200086(KOKAI)).
Furthermore, there is also an example in which it is proposed to cope with a change of the environment rapidly by using the UWB (Ultra WideBand) for communication of control signals in conventional cognitive radio communication systems (See “Implementation Issues in Spectrum Sensing for Cognitive Radios,” Danijera Cabric, Shridhar Mubaraq Mishra, Robert W. Brodersen, Berkeley Wireless Research Center, Asilomar Conference on Signals, Systems and Computers, 2004)
In the conventional scheme described in the above JP-A 1997-200086(KOKAI), however, the available frequency channels are merely selected in order of less interference. Even if frequency channels having less interference exist in the available frequency channels, therefore, it cannot be said that the frequency channels having less interference are enough utilized efficiently.
In the latter-cited conventional scheme, it is necessary to provide a wireless communication apparatus capable of performing two communications of an ordinary cognitive radio communication and a UWB wireless communication. A problem is posed from the viewpoint of reducing the size and power consumption of the wireless communication terminal.